I admit that talking about the future
is one of the most confusing aspects of English. We don't just think
about when we're going to do something, we also take into account how
we consider it.

In Spanish there's not much difference
between lo haré mañana and lo voy a hacer
mañana. In English, however, we receive unspoken information
according to what people say. I'll do it tomorrow, for example,
tells us that the decision to do it has just been made. I'm going
to do it tomorrow tells us that the decision was made earlier
and that it is now an intention.

This may sound confusing, but in
fact it's very precise. Just a little difficult at first...

Will

Structure: willdo something

Will is
used to talk about a future fact:

He'llbe 24
tomorrow.
The Mayor willopen the
new musem next Tuesday.
The money willgo into
your account at the end of the month.

Will can
be used to make a prediction:

I think it will be hot
and sunny tomorrow.
If you take an aspirin, you'll soon feel better.
Valencia willwin the
league this year.

Will is
also used to express an intention or decision made at the moment of
speaking. Immediately after this decision, going
to is probably the most appropriate form to use:

It's very hot in here. I'llopen the
window.
I'll have a cheeseburger
and large fries.
Pub or cinema? No, I think I'llstay
in instead.

Going
to

Structure: going
todo something

Going to is
used to talk about a future intention when a decision has already been
made:

When I leave university, I'm going
to be a doctor.
They're going tomeet us
in the pub after the film.
When I leave school I'm going (togo)
to university.

When we use 'going
togo', we often omit 'togo'
and just say 'going'.

Going to is
also used to talk about future predictions when there is evidence that
something is going to happen:

Look at those clouds. It's going
torain.
I haven't done any revision. I'm going tofail the
exam.
He's beaten all the other players. He's going toscore!

Present
simple

The present simple is used to talk
about future timetables, itineraries and so on.

Spanish people are not generally
happy using this because it sounds strange to them. However, English
people use it all the time to refer to the future.

It's used to talk about future arrangements
(a word which doesn't have an exact translation in Spanish). An arrangement
is similar to an intention, but involves more preparation or organisation.
In other words you have to phone someone, or put it in your diary,
or promise yourself something.

I'm having
lunch with my parents tomorrow. (I rang them)

He's leaving work at the end of the month. (He's
told his boss)

She's meeting me in the pub later. (We spoke
to each other at the end of class)

I'm seeing that film tomorrow afternoon. (I
promised myself)

Future
continuous

Structure: will be
doing something

The future continuous is used to
talk about an activity that will be in progress before and after a
particular time:

Don't ring me at 9 o'clock. I'llbe
having dinner.
This time next week I'llbe
lying on the beach wondering what to have for lunch.
Don't come so early. I'll still be
getting ready.

It is also used to refer to a future
event that will happen in the normal course of things, in other words
it doesn't have anything to do with intentions, time of decision, type
of plan etc. This event will occur as time passes. Imagine how you
use the present continuous to talk about what's happening now (I'm
using my computer, etc). Now think about the future, and that's how
we use the future continuous (I'll still be using my computer in half
an hour).

The guests willbe
arriving any minute now.
The company willbe opening a
new branch in London next year.
The teachers will soon be
giving you details of next year's course.

Future
perfect

Structure: willhave
done something/willhave
been doing something

The future perfect is used to talk
about an action that will be completed before a specific time in the
future.

I'llhave
finished the report by 6 o'clock.
They willhave decorated the
house before we move in.
They'llhave been married
fifty years next anniversary.
You'llhave received payment
by the end of the week.
He'llhave been working for
the same company for thirty years next month.